The invention relates to a water supplying device of a hand-held power tool, wherein the water supplying device comprises a water-conducting line and a valve arrangement arranged in the line and comprising a shut-off valve for controlling a water flow flowing through the line.
Hand-held power tools comprising a water supply through which, for example, cooling water is supplied to the tool of the power tool and/or to the workpiece are known. Particularly in the case of a hand-held cut-off machine, the cutting wheel can be supplied with water for binding dust produced when performing a cut.
The control or regulation of the supplied amount of water is not satisfactory in the known embodiments. By means of an external valve, the water flow can be released before beginning the work to be performed and can be interrupted after completion. After release of the water flow, the water flows to the location to be worked on even when the power tool is not in operation. Before and after the actual working steps as well as during short work interruptions, unwanted quantities of water escape that, in addition to increasing water usage, also compromise the location to be worked on with an unnecessary quantity of water.
U.S. Pat. No. 6,442,841 B1 discloses an arrangement with a device for supplying water to a hand-held power tool in which a shut-off valve for opening or closing a water line is provided. The shut-off valve is actuatable by means of a throttle trigger lock with which also the throttle trigger for adjusting the output of the drive motor can be released. By actuating the throttle trigger lock, a water supply is provided only when readiness to operate the working tool with power is indicated by releasing the throttle trigger.
A disadvantage of the disclosed arrangement is that water can escape when performing a function control of the actuating elements, in particular, of the throttle lock even without operation of the working tool, for example, when the motor is standing still. An adjustment of the conveyed amount of water is difficult as is the adjustment in regard to different water pressure available at the intake. Coupling the throttle lock to the shut-off valve leads to stiff operation. When the valve is dirty, stiff and/or damaged, the basic functions of the power tool, such as simple acceleration or performing a dry cut, are made difficult.
The invention has the object to provide a device for supplying water to a hand-held power tool that enables an improved adjustment of the conveyed quantity of water to the actual water demand.